Manufacture of foils and artificial products



March 23, 1937. M HAGEDORN ET 2,074,647

MANUFACTURE OF FOILS AND ARTIFICIAL PRODUCTS Filed June 27, 1935 Patented 23;J 1937. i

-MANUFAorUnr-ior roms -AND l rnonuc'rs Max Hagedorn and Armin Ossenbmnner, Dessauin-Anhalt, Germany, assignors to Agfa Ansco Corporation, Binghamton, N. Y.. a corporation of New York Application June 27, 1933, Serial No. 677,930` In Germany July 2, 1932 comms.

, Our present invention relates to the manufacture of antistatic articles.Y

One oi its objects is to provide moulded articles which have the property to prevent defects due toelectrical discharges. Further objects will be seen from the detailed speciication following hereafter, p

In the accompanying drawingv Fig. 1, Fig. 2, and Fig. 3 are diagrammatic sections of three embodiments according `to this invention applied to a photographic film. V It is well known that sheets or films and other artificial products manufactured from cellulose derivatives, polyvinylchlorids,v and -similar matellirials, as well as highly dry gelatin and casein sheets become easily charged by static electricity. This property is frequently very troublesome; for instance, in the case of photographic iilms made from nitrocellulose or. acetyl cellulose, the photo- 20 graphic emulsion layer is liable to so-called static markings which `are capable ,of development and thus spoil the lm. Furthermore, sparks produced While preparing, treating, and, more particularly, unwinding celluloid iilms have sometimes given rise to ignition of the film. It is also undesirable that very thin foils of polyvinylchloride or acetyl cellulose, such as are used for the manufacture of cigarette tips or for purposes of Iche textile industry, should receive static charges -as such thin foils when thus charged, tenacious- 1y stick to non-conductors, and can be removed therefrom without injury only with diiliculty.

According to this invention a sheet or foil made from a highly polymeric colloid can largely be preserved from static charges by the applicationv in its manufacture of a polymeric aliphatic 'or' aromatic carboxylic acid,` or a salt thereof. Whereasthe anti-static eifect of -most of the additions y which hitherto were recommendedfor reducing the electric excitability,is due merely to their hygroscopicproperties so that the articles treated with these additions absorb a skin of water, and often fail to be effective when the articles are in a dry condition, the l substances used according to this invention remain active even when thoroughly dry.- Instead lof the/free acid or a salt thereof, there may be empy /yed 'a mixed polymerization product or con ensation product which contains the acid or a salt fthereof. In this case the degree of eiiciency depends on the amount of the polymeric acid or its salt present in the mixed polymerization product or mixed condensation -product 55 used. The selection ofthe free 'acidsror the salts depends on the solubility and on the intensity of the effect required.

Materials which'can be made into fllm and threads 4are electriable highly polymeric colloids, for instance, *cellulose derivatives, poly- 'vinyl compounds (esters, polyvinyl alcohol/aldehyde condensation products), albumen derivatives, such as gelatin and similar substances.l

Among the highly polymeric aliphatic or aromatic carboxylic acids, for instance the following' are suitable: Polyglucuronic acid, polyacrylic acid, and polystyrolcarboxylic acid, and the a1- kali salts of these acids. Furthermore there may be used: mixed polymerization products, for instance, from a mixture of vinylchloride and acrylic acid, of nitrilo-acrylic acid and acrylic acid, of styrol and acrylicacid, of vinyl-methyl ether, nitrilo-acrylic acid and styrolcarboxylic acid, and the salts thereof. These compounds may be combined with the lms during their manufacture or, as it is often preferred, may be combined with the iilms as a separate layer and thus, in many cases, may substitute the layers hitherto employed, for instance, layers of gelatin.

The accompanying drawing shows the invention applied to a photographic i'llm. In Fig. 1 the support l is made from an electriiiable highly polymeric colloid, for instance cellulose acetate with the addition of 'a polymeric carboxylic acid. This support bears the light sensitive layer 2.

In another embodimentk shown in Fig. 2 the support l is made from an electriable highly polymeric colloid, for instance cellulose acetate. The light sensitive layer 2 is connected with the support I by means of the adhesive layer 3 containing a substantial amount of polymeric carboxylic acid or a salt thereof. Still another embodiment is shown in Fig. 3. In this figure I is the supportv consisting of an electrifiabler` highly Apolymeric colloid, forinstance cellulose acetate coated on one side with the light sensitive emulsion layer 2, and on the other side with the antistatic layer l, consisting of or comprising a substantial amount of polymericV carboxylic acid or a salt y thereof. Y

The following examples illustrate the invention:

Example 1 which, even when dried for several hours at 80 C., is capable of immediately discharging a charged electrometer, is coated with a photographic emulsion on its tWo sides, Without any previous treatment being applied, and can be employed in X-ray Work.

Example 2 A 1A per cent. solution of the polyacrylic acid derivative of Example 1 in a mixture of equal parts of methyl alcohol and ethyl alcohol is applied on a lm of 130i thickness. The lm thus coated may be made into a cinematographic film, a color-screen lm, a photographic film, or the like. 'I'he lm has such an anti-static power that even after rubbing the coated unexposed film, no marking due to an electric charge is noticeable on the developed lm. l

Example 3 A foil of 30a thickness made from polyvinylchloride is treated with a 1/2 per cent. solution of methylene chloride and a polymerization product from a mixture of 75 per-cent. of polyvinylchoride 5 and 25 per cent. of polyacrylic acid. In contrast to an untreated foil, the treated foil shows, when unwinding it from the bobbin, no sticking properties as due to static charge.

Example 4` The addition of 20 to 50 per cent. of a substance obtained by saponifying the polymerization product froma mixture of 95 per cent. of polyacrylic methyl ester and 5 per cent. of nitrilo-polyacrylic 35 acid transformed into'the free acid, to nitrocellulose produces a diminution of the electric excitability. Such films are preferably used for the manufacture of photographic lms of any kind.

zation product from a mixture of 40 per cent. of nitrilo-acrylic acid, and 60 per cent. of sodium acrylate attached to one side of said support, and a light sensitive layer attached to said layer of said polymerization product.

3. A moulded article comprising an electriable highly polymeric colloid and a compound selected from the group consisting of an alkali metal salt of a polymeric carboxylic acid, mixed polymerization products containing an alkali metal salt of a polymeric carboxylic acid, and mixed condensation products containing an alkali metal salt of a polymeric carboxylic acid.

4; A photographic lm comprising a support comprising an electriflable highly polymeric colloid and a compound selected from the group consisting of an alkali metal salt of a polymeric carboxylic acid mixed polymerization products containing an alkali metal salt of a polymeric carboxylic acid, and mixed condensation products containing an alkali metal salt of a polymeric carboxylic acid, and attached to at least one side ofthis support a light-sensitive layer.

5. Av photographic lm comprising a support consisting of an electriable highly polymeric colloid, an adhesive layer, attached to at least one side of said support, said adhesive layer comprising a compound selected from the group consisting of an alkali metal salt of a. polymeric carboxylic acid, mixed polymerization products containing an alkali metal salt of a polymeric carboxylic acid, and mixed condensation products containing an alkali metal salt of a polymeric carboxylic acid and a light-sensitive layer attached to said adhesive layer.

6. A photographic film, comprising a support consisting of an electriable highly polymeric colloid, a layer comprising a compound selected from the group consisting of an alkali metal salt of a polymeric carboxylic acid, mixed polymerization products containing an alkali metal salt of a polymeric carboxylic acid, and mixed condensa-.-

tion products containing an alkali metal salt of a polymeric carboxylic acid and a light-sensitive layer, attached to the other side of said support.

MAX HAGEDORN. ARMIN OSSENBRUN'NER. 

